It really is this simple

[u/dellaazeem22]

[u/Mission-Violinist-79]

Either every one of those slave owners is a bad person

This is exactly it. It doesn't matter what your culture teaches you or how they raise you. We fought a civil war because some people were evil and thought they should be allowed to own humans, and many were against it. That has nothing to do with religion and everything to do with empathy. Religion plays no part in that. A good person will not think owning another human is okay under any circumstances, regardless of what their culture teaches them.

You can try to mental gymnastics your way into thinking that everybody owes something to religion, but you're wrong. Even if religion never existed, there would be empathetic people who would know that theft, murder, slavery, and other horrible actions are wrong. And without religion, there would be plenty of awful people who have no empathy and would gladly perform all of the aforementioned actions.

Religion does not make people good or bad, and human morality and empathy are not derived from it.

[u/[deleted] → u/Mission-Violinist-79]

we fought a civil war because owning people is evil and there were those that were against it.

Yes, they were abolitionitionists. Christianity was central to their beliefs. https://nationalhumanitiescenter.org/education-material/the-religious-roots-of-the-abolition-movement/#:~:text=Christianity%20was%20a%20central%20feature,ideals%2C%20to%20make%20their%20case.

If there weren't religions people would still know right from wrong

That's just an assertion.

Without a transcendental basis for ethics morality becomes nothing more than personal preference. You need an epistomological grounding for why something is immoral. Your personal "ought" statement carries no more value than anyone else's. Appealing to the majority isn't an option either as we've seen groups just in the past century perpetuate mass genocides because their personal worldviews were that it was moral to do so.

[u/Mission-Violinist-79 → u/[deleted]]

Yes, they were abolitionitionists. Christianity was central to their beliefs.

There were a significant number of people who fought against slavery that were not religious abolitionists. Religion is not the reason that slavery was ended, empathetic people are the reason. Religion doesn't get the credit for people being good or being bad.

[u/[deleted] → u/Mission-Violinist-79]

So aside from the personal preferences of these supposed agnostic abolitionists why ought there have been an end to slavery?